1. Field of the Invention
The present invention relates to a recording medium fixing a hologram, and a hologram reader to read the hologram from the recording medium.
2. Description of the Related Art
In recent years, a recording medium of the card type having a magnetic storage and/or an IC chip has widespread. For example, there is a credit card storing the information for authorization of the principal. Also, there is a personal ID card in which a face photograph is bonded on the recording medium, with the name described. This personal ID card is employed as a membership card or a pass.
In this way, since such recording medium is often employed for the purposes of personal authorization, it is necessary to take a security measure to prevent the information stored in the magnetic storage area from being illegally rewritten or forged.
In this recording medium, the magnetic storage area is basically a rewritable memory, which can not fully prevent forgery. Thus, with a technique as disclosed in JP-A-2000-348149, a hologram having the characteristic that the new information can be added, but the information written in the past can not be altered is employed.
However, the conventional technique as disclosed in JP-A-2000-348149 had the following problems. That is, in these days, the fingerprint or iris information (so-called biometrics information) intrinsic to the personal is often employed to make personal authorization more adequate. When the technique as disclosed in JP-A-2000-348149 is employed, it is required to store the biometrics information for personal authorization in a database, whereby there is a great management load not to illegally leak the biometrics information from the database.
Also, in the registration of database, the biometrics information is recorded as the digital information, and easily copied in full form owing to the characteristics of the digital information, which is one cause of increasing the management load of the database.
Moreover, the technique as disclosed in JP-A-2000-348149 can not deal with a case where the hologram itself is forged.